Dressings, systems, and methods for treating a wound on a patient&#39;s limb employing liquid control

ABSTRACT

Wound dressings, systems, and methods are presented for treating a wound on a patient&#39;s limb, such as a venous leg ulcer. The dressings, systems, and methods involve creating airflow within the dressing to vaporize and remove liquid. The airflow may begin when the dressing becomes saturated. The dressings may be used to provide compression and reduced pressure to the wound. Other systems, methods, and dressings are presented herein.

RELATED APPLICATIONS

The present invention claims the benefit, under 35 USC §119(e), of the filing of U.S. Provisional Patent Application Ser. No. 61/558,544, entitled “Dressings, Systems, and Methods for Treating a Wound on a Patient's Limb Employing Liquid Control,” by Pratt et al., filed Nov. 11, 2011, which is incorporated herein by reference for all purposes.

FIELD

The present disclosure relates generally to medical treatment systems suitable for use with venous leg ulcers (VLU) and, more particularly, but not by way of limitation, to dressings, systems, and methods for treating a wound on a patient's limb, e.g., a venous leg ulcer, that employs liquid control or management.

BACKGROUND

Venous leg ulcers (VLU), which are sometimes called varicose or stasis ulcers, result from damage to the valves in the veins of the legs, leading to raised venous pressure. VLUs have a multi-faceted negative effect on the health and wellbeing of patients. Physical symptoms include pain and immobility, which in turn, may lead to sleep disturbance, lack of energy, work limitations, frustration, and a lack of self-esteem.

The main treatment has been the application of compression to minimize edema or swelling. Compression treatments include wearing compression stockings, multi-layer compression wraps, or wrapping an ACE bandage or dressing from the toes or foot to the area below the knee. Other wounds may also be experienced on limbs of a patient.

SUMMARY

According to an illustrative embodiment, a wound dressing for treating a wound on a patient's limb includes a tubular sleeve member for receiving the patient's limb and a pressure source fluidly coupled to the tubular member. The tubular sleeve member includes an elastic compression member formed as a sleeve having a first side and a second, patient-facing side and a fluid-directing member having a first side and a second, patient-facing side. The first side of the fluid-directing member is disposed proximate to the second, patient-facing side of the elastic compression member. The fluid-directing member is operable to inhibit fluids from flowing through the fluid-directing member. The tubular sleeve member also, includes a pathway member having a first side and a second, patient-facing side. The first side of the pathway member is proximate to the second, patient-facing side of the fluid-directing member. The pathway member is operable to transport a fluid under a pressure gradient. The pressure source is fluidly coupled to the pathway member for moving fluid therein. The wound dressing further includes at least one exhaust port fluidly coupled to the pathway member for allowing fluids to exit the wound dressing. The tubular sleeve member may also include one or more of the following: an absorbent member, a transition member, or a patient-interface member.

According to another illustrative embodiment, a dressing for treating a wound on a patient's limb includes a means for compressing the limb proximate the wound and a means for receiving liquid from the wound into the dressing. The dressing further includes a means for forcing air to flow through the dressing to facilitate vaporization and removal of liquids from the dressing.

According to another illustrative embodiment, a method for treating a wound on a patient's limb includes providing a wound dressing. The wound dressing includes a tubular sleeve member that includes an elastic compression member formed into a sleeve having a first side and a second, patient-facing side and a fluid-directing member having a first side and a second, patient-facing side. The first side of the fluid-directing member is disposed proximate to the second, patient-facing side of the elastic compression member. The fluid-directing member is operable to inhibit fluids from flowing through the fluid-directing member. The tubular sleeve member further includes a pathway member having a first side and a second, patient-facing side. The first side of the pathway member is proximate to the second, patient-facing side of the fluid-directing member. The pathway member is operable to transport a fluid under a pressure gradient. The method further includes disposing the wound dressing around the patient's limb proximate to the wound, receiving liquid from the wound into the wound dressing, and creating a pressure gradient within the wound dressing to cause air flow in the wound dressing to evaporate liquid from the wound dressing. The air enters the wound dressing at one location and is exhausted at another location.

According to another illustrative embodiment, a method of manufacturing a wound dressing for treating a wound on a patient's limb includes forming a tubular sleeve member for receiving the limb of the patient. The step of forming a tubular sleeve member includes forming an elastic compression member as a sleeve having a first side and a second, patient-facing side; forming a fluid-directing member having a first side and a second, patient-facing side; and disposing the first side of the fluid-directing member proximate to the second, patient-facing side of the elastic compression member. The fluid-directing member is operable to inhibit fluids from flowing through the fluid-directing member. The step of forming a tubular sleeve member further includes forming a pathway member having a first side and a second, patient-facing side and disposing the first side of the pathway member proximate to the second, patient-facing side of the fluid-directing member. The pathway member is operable to transport a fluid under a pressure gradient. The method of manufacturing a wound dressing further includes fluidly coupling the pressure source to the pathway member for moving fluid therein.

According to another illustrative embodiment, a system for treating a wound on a patient's limb includes a wound dressing comprising a tubular sleeve member. The tubular sleeve member includes a plurality of pressure compartments. Each pressure compartment is operable to form a pressure gradient on a portion of the patient's limb. The system further includes a pressure source that is fluidly and separately coupled to each of the pressure compartments; and a controller coupled to the pressure source to, control pressure delivery to the plurality of pressure compartments. The controller and pressure source are operable to cause a first pressure compartment of the plurality of pressure compartments to compress around the patient's limb, then subsequently a second pressure compartment of the plurality of pressure compartments to compress in order to encourage fluid movement in the patient's limb from proximate the first pressure compartment towards the second pressure compartment.

According to another illustrative embodiment, a method for treating a wound on a patient's limb includes forming a plurality of pressure compartments on the patient's limb proximate the wound, sequentially compressing each pressure compartment in a cephaladic direction, and flowing air over a majority of the pressure compartments to vaporize and remove liquid.

Other aspects, features, and advantages of the illustrative embodiments will become apparent with reference to the drawings and detailed description that follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevation view of an illustrative embodiment of a dressing for treating a venous leg ulcer or other wound on a patient;

FIG. 2 is a cross section (medial) of the dressing of FIG. 1 taken along line 2-2;

FIG. 3 is a cross section of a portion of an illustrative embodiment of a wound dressing for treating a wound, such as a venous leg ulcer, that shows another seal against a patient's epidermis;

FIG. 4 is a perspective view of an illustrative embodiment of a dressing for treating a wound, such as venous leg ulcer or other wound;

FIG. 5 is a cross section of a portion of another illustrative embodiment of a dressing for treating a wound, such as venous leg ulcer;

FIG. 6 is a cross section of a portion of another illustrative embodiment of a dressing for treating a wound, such as venous leg ulcer;

FIG. 7 is a cross section of a portion of another illustrative embodiment of a dressing for treating a wound, such as venous leg ulcer;

FIG. 8 is a cross section of a portion of another illustrative embodiment of a dressing for treating a wound, such as venous leg ulcer;

FIG. 9 is a cross section of another illustrative embodiment of a dressing for treating a wound, such as venous leg ulcer;

FIG. 10 is an elevation view of an illustrative embodiment of a dressing for treating a wound, such as venous leg ulcer, on a patient;

FIG. 11 is a schematic diagram of a control subsystem for use with a dressing for treating a wound, such as venous leg ulcer; and

FIG. 12 is an elevation view of another dressing for treating a wound, such as venous leg ulcer, on a patient.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

In the following detailed description of the illustrative, non-limiting embodiments, reference is made to the accompanying drawings that form a part hereof. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is understood that other embodiments may be utilized and that logical structural, mechanical, electrical, and chemical changes may be made without departing from the spirit or scope of the invention. To avoid detail not necessary to enable those skilled in the art to practice the embodiments described herein, the description may omit certain information known to those skilled in the art. The following detailed description is not to be taken in a limiting sense, and the scope of the illustrative embodiments are defined only by the appended claims.

In treating a venous leg ulcer (VLU) or other wounds, it is desirable to apply compression, remove exudate, and control the liquid produced by the wound that is retained in a dressing. VLU's produce considerable liquids that can saturate a dressing, cause an undesirable odor, and cause maceration of healthy skin. The dressings and systems herein control the liquid from the wound in a way to avoid one or more of these conditions.

Referring to the figures, and initially to FIGS. 1-2, a dressing 102 for treating a wound 104, such as a venous leg ulcer, on a limb 106 or extremity of a patient 108 is presented. The wound 104 may involve epidermis 103, dermis 105, and subcutaneous tissue 107. The dressing 102 reduces the amount of liquid from the wound 104 that is retained within the dressing 102 by using air movement to vaporize and remove fluids. The dressing 102 may reduce odor and may facilitate an overall smaller size dressing than might otherwise be possible. The dressing 102 may have a longer use time than otherwise possible.

The dressing 102 includes a tubular sleeve member 110 for receiving the limb 106 or extremity of the patient 108. The tubular sleeve member 110 has limb openings 112: a first limb opening 114 and a second limb opening 116. The limb openings 112 allow the tubular sleeve member 110 to receive the limb 106 therein. The tubular sleeve member 110 and the limb openings 112 may be sized to accommodate different sized limbs 106.

The tubular sleeve member 110 may include an elastic compression member 118 formed as a sleeve. The elastic compression member 118 is the outermost (furthest from patient 108) member of the tubular sleeve member 110. The elastic compression member 118 has a first side 120 and a second, patient-facing side 122. The elastic compression member 118 may be formed from one or more of the following materials: Nylon Powernet material; Velband; materials with combinations of relatively non-elastic nylon fibers and highly-elastic fibers (e.g., Spandex, Elastene); Lycra materials, stretch cotton; rubber materials; urethanes; silicones; or other stretch based materials. The elastic compression member 118 is optional in that an embodiment may be used as a dressing without this layer. In such a case, the next layer, a fluid-directing member 124, may securely hold the dressing 102 in place.

The tubular sleeve member 110 also includes the fluid-directing member 124, The fluid-directing member 124 has a first side 126 and a second, patient-facing side 128. The first side 126 of the fluid-directing member 124 is disposed proximate to the second, patient-facing side 122 of the elastic compression member 118. The fluid-directing member 124 is operable to inhibit fluids from flowing through the fluid-directing member 124. The fluid-directing member may comprise one or more of the following a polyurethane (PU) drape; an elastomer (e.g., natural rubbers, polyisoprene, styrene butadiene rubber, chloroprene rubber, polybutadiene, nitrile rubber, butyl rubber, ethylene propylene rubber, ethylene propylene diene monomer, chlorosulfonated polyethylene, polysulfide rubber, EVA film, co-polyester, and silicones; silicone drape material; a 3M Tegaderm® drape; or a polyurethane (PU) drape. The fluid-directing member 124 directs fluids so that airflow is primarily out of the exhaust ports.

At the limb openings 112, the fluid-directing member 124 may extend beyond any other layers to form an extension 130. The extension 130 forms a seal with the patient's epidermis 103 as shown best in FIG. 2. The extension 130 has a first side 134 and a second, patient-facing side 136. An adhesive 138 is applied to the second, patient-facing side 136 of the extension 130 to facilitate attachment to the patient's epidermis 103. A port 140, which depending on mode of operation is an intake port or an exhaust port, is formed through the fluid directing member 124 and any other members as necessary to access air beyond the wound dressing 102. The port 140 allows fluid to enter or exit the wound dressing 102.

As shown in FIG. 3, in another illustrative embodiment, the elastic compression member 118 and fluid-directing member 124 both extend over transverse edges 142 and, because of compression, impinge upon the epidermis 103 to form a seal. In this embodiment, the port 140 extends through both the elastic compression member 118 and fluid-directing member 124. In still another embodiment, all the layers may be coterminous and the entire edge may serve to exhaust vapor.

Referring again primarily to FIG. 2, the tubular sleeve member 110 further includes a pathway member 144. The pathway member 144 has a first side 146 and a second, patient-facing side 148. The first side 146 of the pathway member 144 is proximate to the second, patient-facing side 128 of the fluid-directing member 124. The pathway member 144 is operable to transport a fluid under a pressure gradient. The pathway member 144 functions to present pathways that allow a gas to flow and has sufficient rigidity to allow pathways to remain open even when compressed during use. The pathway member 144 may comprise one or more of the following: open-cell foam; non-woven material (e.g., Libeltex Hydrophobic non-woven); or Vilmed range from Freundenberg 1522. As suggested by arrows 150 in FIG. 2, air moves within the pathway member 144. Arrows 150 show airflow in one direction, but another direction is possible as is explained elsewhere.

The tubular sleeve member 110 may optionally include an absorbent member 152. The absorbent member 152 at least temporarily retains liquids from the wound 104 away from the patient's epidermis 103. The absorbent member 152 has a first side 154 and a second, patient-facing side 156. The first side 154 of the absorbent member 152 is proximate to the second, patient-facing side 148 of the pathway member 144. The absorbent member 152 acts as a buffer to hold liquid from the wound 104 while waiting for the liquid to be evaporated and carried away by airflow in the pathway member 144. The absorbent member 152 may be any material that functions to hold liquid. The absorbent member 152 may be formed from one or more of the following: a super absorbent polymer material (e.g., LUQUAFLEECE from BASF), Vilmed range from Freundenberg 1522, or other material.

The tubular sleeve member 110 may optionally include a transition member 158. The transition member 158 may be formed from the same materials as the pathway member 144. The transition member 158 has a first side 160 and a second, patient-facing side 162. The first side 160 of the transition member 158 is disposed proximate to the second, patient-facing side 156 of the absorbent member 152. The transition member 158 wicks liquids from the wound 104 to help keep fluids away from the epidermis 103 or wound 104.

The tubular sleeve member 110 may optionally include a patient-interface member 164 that has a first side 166 and a second, patient-facing side 168. The first side 166 of the patient-interface member 164 is disposed proximate to the second, patient-facing side 162 of the transition member 158 or the second, patient-facing side 156 of the absorbent member 152. The second, patient-facing side 168 of the patient-interface member 164 is for disposing proximate to the patient 108. The patient-interface member 164 is designed to be against the epidermis 103 for extended periods of time and may include an anti-microbial material, e.g., silver. The patient-interface member 164 may be formed from a Silver Miliken or other material.

A pressure source 170 is fluidly coupled to the tubular sleeve member 110. The pressure source 170 may be, for example, a reduced-pressure source or a positive pressure source. Thus, the pressure source 170 may be a micro-pump 172 as shown in FIG. 2, a remote reduced-pressure source 174 as shown in FIG. 10, a wall-based suction source, or a wall-based positive pressure source.

As suggested by arrows 176 in FIG. 1, the pressure source 170 may be configured to pull air into the wound dressing 102 at an inboard location. The wound dressing 102 may be configured to discharge the air at the edges. The air is discharged through one port 140 at the limb opening 112 as suggested by arrows 178. Alternatively, the pressure source 170 may be configured to pull air as suggested by arrows 180 in FIG. 10 from the limb openings 112 to the pressure source 170 and then exhaust the air at the reduced-pressure source 174.

The wound dressing 102 includes at least two ports: port 140 and port 182. The limb openings 112 typically include at least one port 140. As shown best in FIG. 4, a plurality of ports 140 may be included. The port or ports 140 may function as exhaust ports or intake ports depending on the configuration of the pressure source 170. Thus, in FIGS. 1-2, the port 140 is an exhaust port. In FIG. 10, the ports 140 are intake ports. The port 182 is associated with the pressure source 170 and may include an extension portion 185 to provide fluid communication with a desired layer of the wound dressing 102. For example, the extension portion 185 may fluidly couple the pressure source 170 to the pathway member 144 as shown in FIG. 2 or to another layer if desired.

The pressure source 170 causes a pressure gradient in the wound dressing 102 that will move air. Depending on how the wound dressing 102 is configured, air either enters at the edges (e.g., at the limb opening 112) and moves to port 182 or enters at the port 182 and moves to the limb opening 112 and out ports 140. The ports 140 and 182 may both may be inboard if a compartment wall is used as is described elsewhere herein. The pressure gradient is typically established primarily in the pathway member 144, but may be established in other layers in some embodiments.

Each port 140, 182 may have a filter associated with the port 140, 182. For example, a filter 184 is associated with port 140, and a filter 186 is associated with port 182. The filters 184, 186 may be odor filters, e.g., charcoal filters, or anti-bacterial filters. In FIG. 2, the filter 184 is a charcoal filter for removing odor from the airflow before the airflow is released into the atmosphere. The filter 186 is an intake filter for removing bacteria before the air enters the wound dressings 102. In FIG. 10, the intake filters (not explicitly shown) associated with ports 140 are anti-bacterial intake filters.

Of the various layers mentioned (e.g., elastic compression member 118, fluid directing member 124, pathway member 144, absorbent member 152, transition member 158, and patient-interface member 164), some may be omitted, some combined, and some rearranged. As a few non-exhaustive examples, consider the embodiments of FIGS. 5-8. In FIG. 5, the tubular sleeve member 110 of the wound dressing 102 comprises only an elastic compression member 118, a fluid-directing member 124, and pathway member 144. In FIG. 6, the tubular sleeve member 110 of the wound dressing 102 comprises an elastic compression member 118, a fluid-directing member 124, pathway member 144, and an absorbent member 152. In FIG. 7, the tubular sleeve member 110 of the wound dressing 102 comprises an elastic compression member 118, a fluid-directing member 124, pathway member 144, an absorbent member 152, and a transition member 158. In FIG. 8, the tubular sleeve member 110 of the wound dressing 102 comprises an elastic compression member 118, a fluid-directing member 124, and a woven-open-structure member 188. The woven-open-structure member 188 functionally combines the pathway member 144, absorbent member 152, and the transition member 158 into one material. The woven-open-structure member 188 is operable to retain fluids and at the same time allow gases to move in the woven-open-structure member 188. The woven-open-structure member 188 may be formed from Vilmed range from Freundenberg 1522 or other similar material, for example.

Referring now to FIG. 9, another illustrative embodiment of a wound dressing 102 for treating a wound 104 on a limb 106 of a patient 108 is presented. The cross section is a medial cross section of the limb 106 with the wound dressing 102 applied thereto. The wound dressing 102 is analogous in most respects to the wound dressing of FIGS. 1-2, except the elastic compression member 118 is omitted and additional features added as will be explained. The wound dressing 102 may be formed as an annular sleeve, as an isolated dressing, or island dressing. The wound dressing 102 may be used with or without compression. If compression is desired, the compression is developed by application of the fluid-directing member 124 in tension. The wound dressing 102 is held by adhesive 138 to the patient 108.

In this embodiment, a control subsystem 202 is included. The control subsystem 202 includes at least one saturation sensor 190. The saturation sensor 190 is coupled to the absorbent member 152. In other embodiments, the saturation sensor 190 may be coupled to other layers, e.g., the transition member 158. The saturation sensor 190 may be a galvanic cell with two electrodes that produce voltage when saturated, a resistive pathway that is completed by exudate, or a capacitor-based sensor.

The saturation sensor 190 is coupled to a control circuit or controller 192. The controller 192 is configured to monitor the saturation sensor 190. When the controller 192 detects a change indicative that the absorbent member 152 is saturated or partially saturated, the controller 192 activates the pressure source 170 in response. The pressure source in this embodiment pulls gas from the port 182 and discharges the gas to the atmosphere as suggested by arrows 194. The air is pulled from the transverse edges 142 through one or more ports 140. In this embodiment, the ports 140 may have a control valve 196 associated with each port 140. The control valve 196 may be wirelessly or electrically coupled by a lead 199 to the controller 192. The control valve 196 regulates air flow through the one or more ports 140 to keep air moving in the wound dressing 102, but also to control the rate such that, if desired, a reduced pressure may be maintained in a sealed space 198 at a desired level.

As an alternative to the control valve 196, controlled leaks in the fluid-directing member 124 may be used. The controlled leaks allow air to flow in at or near the transverse edges 142 towards the pressure source 170. For example, apertures (not explicitly shown) in the fluid-directing member 124 may be covered by an adhesive film that is removed later when a leak is desired.

With the embodiment of FIG. 9, a reduced pressure may be applied to the wound 104 and liquids removed and managed. The reduced pressure is initially applied by the pressure source 170. When sufficient liquids reach the absorbent member 152 and saturate the absorbent member 152, the control valve 196 may be at least partially opened to allow some fluid flow into the wound dressing 102 and at the same time the pressure source 170 may be sufficiently increased to hold the desired reduced pressure notwithstanding the introduction of air through ports 140. As shown in the diagram of FIG. 11, a display 200 may be added to the control subsystem 202 to provide feedback to a user. The display 200 may be a series of LED indicators, a bi-stable LCD type, or other compact display. The display 200 is compact and low power. The display 200 may display information such as remaining battery capacity, duration of therapy, and the fill status of the dressing as well as confirmation that the system is operating within its normal parameters.

Referring now primarily to FIG. 10, another illustrative embodiment of a wound dressing 102 for treating a wound 104 on a limb 106 of a patient 108 is presented. The wound dressing 102 is analogous to those previously presented, except in this embodiment, the pressure source 170 is a remote reduced-pressure source 174. The remote reduced-pressure source 174 is fluidly coupled by a pressure conduit 204 to the tubular sleeve member 110. A pressure interface 206 may be used to fluidly couple the pressure conduit 204 to the intake port (see port 182 in FIG. 2). The intake port is at an inboard location on the wound dressing 102. In one illustrative embodiment, the pressure interface 206 is a T.R.A.C.® Pad or Sensa T.R.A.C.® Pad available from KCI of San Antonio, Tex., or another interface. In another embodiment, a “bridge” (an open-cell foam or other passageway material enclosed in a gas-impermeable material) is used to deliver reduced pressure to the wound dressing 102.

Referring now primarily to FIG. 11, the control subsystem 202 includes a controller 192 that is coupled to a saturation sensor 190 and to a pressure source 170. In addition, a control valve 196 may be coupled to the controller 192 and also a display 200. The control subsystem 202 may control the leak rate by opening the control valve 196 when included or may turn on, turn off, increase, or decrease the pressure produced by the pressure source 170. As used through out this document, “or” does not require mutual exclusivity. The control valve 196 may be a solenoid valve such a Pneutronics X valve with a fixed size orifice from Parker Hannifin, Cleveland, Ohio; a mechanical proportional valve; or a PZT proportional valve such as those supplied by Festo.

It should be understood that the control subsystem 202 of FIG. 11 or aspects of the control subsystem 202 may be applied to any of the embodiments herein. Thus, for example, when the control subsystem 202 is added to the wound dressing 102 in FIGS. 1-2, the saturation sensor 190 and controller 192 determine when the absorbent member 152 is saturated or partially saturated. The controller 192 may then activate the pressure source 170 to initiate airflow in the wound dressing 102 to evaporate and remove liquids from the wound dressing 102. The sensor 109 and controller 192 may detect saturation as a scale. The duration of the airflow or the speed of the airflow may be set by the controller 192 in response to the degree of saturation involved. The control system 202 may also display information such as remaining battery capacity, duration of therapy, and the fill status of the dressing as well as confirmation that the system is operating within its normal parameters.

Referring now primarily to FIG. 12, another illustrative embodiment of a wound dressing 102 is presented. The wound dressing 102 is analogous in most respects to the previously presented wound dressings, except in this embodiment, a plurality of pressure compartments 208 are added and are used to massage the limb 106. Each pressure compartment 208 is operable to form a pressure gradient on a portion of the patient's limb 106 to move air for the purposes previously presented. In addition, the pressure compartments 208, which are formed with a plurality of compartment walls 209, allow squeezing or sequenced movement in a cephaladic direction.

A pressure source 170 is fluidly coupled separately to each of the pressure compartments 208 by a plurality of pressure conduits 205. Each pressure compartment 208 has a pressure interface 206 for fluidly coupling the pressure conduit 205 to the pressure compartment 208. Each pressure conduit 205 is also fluidly coupled to the pressure source 170.

A controller 192 is coupled to the pressure source 170 to control pressure delivery to the plurality of pressure compartments 208. The controller 192 and pressure source 170 are operable to cause a first pressure compartment 210 of the plurality of pressure compartments 208 to compress around the patient's limb 106, then subsequently a second pressure compartment 212 of the plurality of pressure compartments 208 to compress around the patient's limb 106 in order to encourage fluid movement in the patient's limb 106 from proximate the first pressure compartment 210 towards the second pressure compartment 212. The coordinated compression of pressure compartments 208 may continue with the others.

The pressure source 170 may have a controller 192 associated with the pressure source 170. The controller 192 may be configured to control a plurality of pumps within the pressure source 170 or a plurality of valves (not explicitly shown) to allow varying pressure within the pressure compartments 208. The controller 192 can sequentially supply a pressure gradient to the pressure compartments 208 to cause sequential compression of the compartments on the patient's limb 106. The sequential compression of each pressure compartment results in moving fluids in the patient's limb in a cephaladic direction (in the direction that goes from the feet towards the head). This motion thus creates a massage like motion on the limb 106. At the same time, as with the previous embodiments, air flow may be introduced into the wound dressing 102 to facilitate evaporation and removal of liquids.

The compression of each pressure compartment 208 may be achieved using positive pressure or reduced pressure from the pressure source 170. If positive pressure is used, the pressure compartments 208 may include bladders that fill to cause compression. If reduced pressure is used, the reduced pressure may cause the fluid-directing member 124 to pull down on the other layers which act as a bolster and thereby generate a compressive force.

With reference generally to the figures, in operation according to one illustrative embodiment, a wound dressing 102 is provided. The wound dressing 102 may be any of those presented or suggested herein or combinations thereof. The wound dressing 102 includes a tubular sleeve member 110. The wound dressing 102 is disposed around the patient's limb 106 proximate to the wound 104. This may entail sliding the patient's limb 106 through the limb openings 112 or using an open and closeable seam (not explicitly shown).

Once the wound dressing 102 is in place on the limb 106, the wound dressing 102 may receive liquid from the wound 104 into the wound dressing 102. Either all the time, in response to saturation or partial saturation, or based on a timer, the pressure source 170 is activated. The pressure source 170 creates a pressure gradient within the wound dressing 102 that causes air flow in the wound dressing 102 to evaporate liquid from the wound dressing 102. The air enters the wound dressing 102 at one location (e.g., port 182 or port 140) and is exhausted at another location (e.g., port 140 or 182).

The air typically will travel within the wound dressing 102 at a rate of at least 0.1 m/s and is typically in the range 0.01 (or less) to 0.2 m/s. If a saturation sensor 190 and controller 192 are included, they may detect when the saturation has dropped below a threshold level and then signal the pressure source 170 to cease. With spaced intake and exhaust ports, the air will flow over a large portion of the interior of the wound dressing 102. For example, the air may flow over 50 percent, 75 percent, 90% percent or more of the surface area of the pathway member 144 (or other layer if coupled to another layer).

In operation according to another illustrative embodiment, reduced pressure may also be applied to the wound 104 as an aspect of treatment. For example, with respect to FIG. 9, the control valve 196 may remain closed or restricted while reduced pressure is applied to the sealed space 198 to allow the creation of reduced pressure in the sealed space 198. The pressure may be, for example, without limitation, in the −25 mm Hg to −200 mm Hg range. If saturation is detected, the control valve 196 may be opened to allow for increased air flow. In addition, the output of the pressure source 170 may be increased to allow the reduced pressure level to be maintained in the sealed space 198 notwithstanding the leak or bleeding of air.

The air entering or exiting the wound dressing 102 through ports 140 and 182 may first go through a filter 184, 186. The filters 184, 186 remove bacteria or odor. The intake filter will keep bacteria from entering the wound dressing 102 and potentially infecting the wound 104. The exit filter helps remove particulates or remove odors. The configuration of the pressure source 170 determines whether a filter is an intake filter or exit filter.

According to another illustrative embodiment, a method of manufacturing a wound dressing 102 for treating a wound 104 on a patient's limb 106 is contemplated. The method includes forming a tubular sleeve member 110 for receiving the patient's lower extremity or limb 106. The step of forming the tubular sleeve member 110 includes forming an elastic compression member 118 as a sleeve having a first side 120 and a second, patient-facing side 122; forming a fluid-directing member 124 having a first side 126 and a second, patient-facing side 128; and disposing the first side 126 of the fluid-directing member 124 proximate to the second, patient-facing side 122 of the elastic compression member 118. The fluid-directing member 124 is operable to inhibit fluids from flowing through the fluid-directing member 124. The step of forming the tubular sleeve member 110 further includes forming a pathway member 144 having a first side 146 and a second, patient-facing side 148 and disposing the first side 146 of the pathway member 144 proximate to the second, patient-facing side 128 of the fluid-directing member 124. The pathway member 144 is operable to transport a fluid under a pressure gradient. The method further includes fluidly coupling the pressure source 170 to, the pathway member 144 for moving fluid therein.

With respect to the preceding method, the step of forming a tubular sleeve member 110 may further include disposing an absorbent member 152, which is for at least temporarily retaining liquids, into the wound dressing 102. The absorbent member 152 has a first side 154 and a second, patient-facing side 156. The first side 154 of the absorbent member 152 is disposed proximate to the second, patient-facing side 148 of the pathway member 144. The step of forming a tubular sleeve member 110 may further include disposing a transition member 158 proximate to the absorbent member 152 or disposing the patient-interface member 164 into the wound dressing 102. One or more layers may be omitted and the order of the layers may be varied.

While air flow through the pathway member 144 is a prominent illustrative embodiment, it should be noted that the wound dressing 102 may be configured to accommodate air flow in others layers except the fluid-directing member 124. Thus, for example and without limitation, the extension portion 185 (FIG. 2) of the port 182 may extend to the absorbent member 152 or the transition member 158 to cause airflow primarily therein.

It should be understood that airflow may be from an inboard location to the transverse edges 142, from the transverse edges 142 to an inboard location, or from an inboard location to another inboard location. With respect to the lastly mentioned flow pattern and with general reference to FIGS. 2 and 3, an embodiment of a wound dressing 102 has the intake port and exhaust port that are both inboard of the transverse edges 142, but separated by a medial compartment wall (not shown, but analogous to compartment wall 209 in FIG. 12 and running medially). In this latter embodiment, the transverse edges 142 are sealed, air enters the intake port proximate to the compartment wall, the air transversely flows around the limb 106, and then the air exits the exhaust port proximate to the compartment wall but on the opposite side from the intake port.

The wound dressings 102 herein may require fewer changes than other wound dressings because of the liquid management, i.e., the liquid removed by the airflow. The liquid management may also avoid maceration on the patient. The wound dressings 102 may provide less odor and bulk than other dressings. The wound dressing 102 may process more liquid over time that the dressing is otherwise capable of retaining.

Although the present invention and its advantages have been disclosed in the context of certain illustrative, non-limiting embodiments, it should be understood that various changes, substitutions, permutations, and alterations can be made without departing from the scope of the invention as defined by the appended claims. It will be appreciated that any feature that is described in connection to any one embodiment may also be applicable to any other embodiment. For example, the control subsystem 202 of FIG. 11 may be added to any of the other embodiments. As another example, pressure compartments 208 of FIG. 12 may be added to any of the other wound dressings 102 herein. As another example, the tubular sleeve members 110 shown in FIGS. 5-8 may be used with any of the wound dressing 102 embodiments herein.

It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. It will further be understood that reference to “an” item refers to one or more of those items. It should be apparent that the power supply is implicitly present.

The steps of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate.

Where appropriate, aspects of any of the embodiments described above may be combined with aspects of any of the other embodiments described to form further examples having comparable or different properties and addressing the same or different problems.

It will be understood that the above description of preferred embodiments is given by way of example only and that various modifications may be made by those skilled in the art. The above specification, examples and data provide a complete description of the structure and use of exemplary embodiments of the invention. Although various embodiments of the invention have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of the claims. 

We claim:
 1. A wound dressing for treating a wound on a patient's limb, the wound dressing comprising: a tubular sleeve member for receiving the patient's limb; wherein the tubular sleeve member comprises: an elastic compression member formed as a sleeve having a first side and a second, patient-facing side, a fluid-directing member having a first side and a second, patient-facing side, wherein the first side of the fluid-directing member is disposed proximate to the second, patient-facing side of the elastic compression member, and wherein the fluid-directing member is operable to inhibit fluids from flowing through the fluid-directing member, and a pathway member having a first side and a second, patient-facing side, wherein the first side of the pathway member is proximate to the second, patient-facing side of the fluid-directing member, wherein the pathway member is operable to transport a fluid under a pressure gradient; a pressure source fluidly coupled to the pathway member and configured to force a gas into the pathway member; at least one exhaust port fluidly coupled to the pathway member for allowing fluids to exit the wound dressing; and at least one filter fluidly coupled to the at least one exhaust port for removing odors.
 2. The wound dressing of claim 1, wherein the tubular sleeve member further comprises: an absorbent member for at least temporarily retaining liquids, the absorbent member having a first side and a second, patient-facing side, wherein the first side of the absorbent member is proximate to the second, patient-facing side of the pathway member.
 3. The wound dressing of claim 2, further comprising a control subsystem, wherein the control subsystem comprises: a sensor fluidly coupled to the absorbent member; and a controller coupled to the sensor and to the pressure source; wherein the sensor, controller, and pressure source are operable to determine when the absorbent member is saturated and to activate the pressure source.
 4. The wound dressing of claim 1, wherein the tubular sleeve member further comprises: an absorbent member for at least temporarily retaining liquids, the absorbent member having a first side and a second, patient-facing side, wherein the first side of the absorbent member is proximate to the second, patient-facing side of the pathway member; and a transition member having a first side and a second, patient-facing side, wherein the first side of the transition member is disposed proximate to the second, patient-facing side of the absorbent member, the transition member wicks liquids.
 5. The wound dressing of claim 1, wherein the tubular sleeve member further comprises: an absorbent member for at least temporarily retaining liquids, the absorbent member having a first side and a second, patient-facing side, wherein the first side of the absorbent member is proximate to the second, patient-facing side of the pathway member; and a transition member having a first side and a second, patient-facing side, wherein the first side of the transition member is disposed proximate to the second, patient-facing side of the absorbent member, the transition member wicks liquids; and a patient-interface member having a first side and a second, patient-facing side, wherein the first side of the patient-interface member is disposed proximate to the second, patient-facing side of the transition member and the second, patient-facing side of the patient-interface member is adapted to be disposed proximate to the patient.
 6. The wound dressing of claim 1, wherein the tubular sleeve member comprises a first limb opening and wherein the at least one exhaust port comprises a plurality of exhaust ports on the first limb opening.
 7. The wound dressing of claim 1, wherein the pathway member comprises a woven-open-structure member that is operable to retain fluids and also allow gases to move in the woven-open-structure.
 8. The wound dressing of claim 1, wherein the pressure source comprises a reduced-pressure source fluidly coupled by a pressure conduit to an intake port on the tubular sleeve member.
 9. The wound dressing of claim 1, wherein the pressure source comprises a reduced-pressure source fluidly coupled to an intake port and a control valve fluidly coupled to the intake port for controlling the rate at which air is allowed into the intake port.
 10. The wound dressing of claim 1, wherein the pressure source comprises a reduced-pressure source fluidly coupled by a pressure conduit to an intake port on the tubular sleeve member, and wherein the pathway member is fluidly coupled to the wound and is operable to deliver reduced pressure to the wound.
 11. The wound dressing of claim 1, further comprising a control subsystem, wherein the control subsystem comprises: a sensor fluidly coupled to the pathway member; and a controller coupled to the sensor and to the pressure source; wherein the sensor, controller, and pressure source are operable to determine when the pathway member is saturated and to activate the pressure source.
 12. A method of manufacturing a wound dressing for treating a wound on a limb of a patient, the method comprising: forming an elastic compression member as a sleeve having a first side and a second, patient-facing side; forming a fluid-directing member having a first side and a second, patient-facing side; disposing the first side of the fluid-directing member proximate to the second, patient-facing side of the elastic compression member, wherein the fluid-directing member is operable to inhibit fluids from flowing through the fluid-directing member; forming a pathway member having a first side and a second, patient-facing side; disposing the first side of the pathway member proximate to the second, patient-facing side of the fluid-directing member, wherein the pathway member is operable to transport a fluid under a pressure gradient; fluidly coupling a pressure source to the pathway member, the pressure source configured to force a gas into the pathway member; fluidly coupling at least one exhaust port to the pathway member for allowing fluids to exit the wound dressing; and fluidly coupling at least one filter to the at least one exhaust port for removing odors.
 13. The method of claim 12, further comprising the step of disposing an absorbent member having a first side and a second, patient-facing side, proximate to the second, patient-facing side of the pathway member, wherein the absorbent member is adapted to at least temporarily retain liquids.
 14. The method of claim 12, further comprising the steps of: disposing an absorbent member having a first side and a second, patient-facing side, proximate to the second, patient-facing side of the pathway member, wherein the absorbent member is adapted to at least temporarily retain liquids; and disposing a transition member having a first side and a second, patient-facing side, proximate to the second, patient-facing side of the absorbent member, wherein the transition member is adapted to wick liquids.
 15. The method of claim 12, further comprising the steps of: disposing an absorbent member having-a first side and a second, patient-facing side, proximate to the second, patient-facing side of the pathway member, wherein the absorbent member is adapted to at least temporarily retain liquids; disposing a transition member having a first side and a second, patient-facing side, proximate to the second, patient-facing side of the absorbent member, wherein the transition member is adapted to wick liquids; and disposing a patient-interface member having a first side and a second, patient-facing side, proximate to the second, patient-facing side of the transition member. 